The invention relates to a device for detecting seat occupancy in a motor vehicle.
German patent document DE 38 43 624 A1 discloses a seat-occupancy-detection device in a vehicle, which has a weight sensor fitted near the base surface of a seat cushion of a seat, and distinguishes between child and adult or non-occupancy, based on pressure exerted on the seat. When the seat-occupancy-detection device senses that the seat is occupied by a passenger, it is possible to activate a drive device to move a headrest which is fitted on the seat, out of a rest position into an operating position.
Another seat-occupancy-detection device, for detecting an occupant in the rear seal of a motor vehicle, is disclosed in U.S. Pat. No. 4,852,934. In this arrangement, when occupancy of the rear seat is detected, rearward movement of the corresponding electrically adjustable front seat is restricted, so that obstruction of the person on the rear seat is prevented.
Still another motor vehicle seat-occupancy-detection device is disclosed in German patent document DE 42 12 018 A1 wherein, when occupancy of the seat is detected, the seat-assigned occupant-retaining system (airbag) is triggered in the event of danger. Moreover, the weight and the position of the occupant who is occupying the seat is taken into account in order to determine the extent airbag inflation.
The object of the present invention is to provide a seat-occupancy-detection device which can be utilized and implemented in a still more versatile manner.
This object is achieved according to the invention, in which in addition to the known functions (for example, of actuability of a headrest as described above), certain seat-assigned safety and comfort functions are automatically actuated based on the load acting on the seat. The area around a seating position is thus automatically adapted based on the seat occupancy, which may assume the values "0"for "not occupied", "K" for "occupied by a child" and "E" for "occupied by an adult", as described hereinbelow for the rear of a vehicle. This feature is made possible by the use of a data bus in the vehicle, which provides the functions connected to the data bus with items of information throughout the vehicle .